Does anyone here have experience doing the hot water bath treatment for nematodes? Last year I saw nematode signs on three different hosta, although I could never find them when I did the test with the cut up leaf in water. So I decided to take a wait and see approach. One of the suspect ones from last year is exhibiting signs again, so I have to assume it is in fact infected. I don't mind throwing it away, along with one other suspect. The third one is one I'd really like to save, so I was thinking of doing the heat treatment. I'm confused as to the best time to do it, though. Have I waited too long in the season and risk having it not come back next year (I understand all the leaves and some roots may die after the treatment). A page on nematodes on the AHS site recommends treating dormant ones in Feb. If I do that, do I just stick a dead looking crown back in some potting soil and leave it outside or what? I'm confused, and am hoping others have done this and can advise. I wish I had thought to do this shortly after the hail storm. This is what the AHS site says:
"2. If this is too extreme, you can "cook" the hosta clump or a piece of the plant. This will kill the nematode eggs in the plant. To cook, use only dormant hostas, I do this in February, about a month before emergence. You can do this in the kitchen sink with tap water and a good thermometer. The proper cooking time is somewhere between 120 degrees F for 20-25 minutes to 130 degrees F for 10 minutes. Try doing different pieces of the same hosta at several bracketed temps and times. The lethal temps and times for hostas are very close to these "recommended" ones, thus you will kill all the roots on the hostas and maybe the whole plant. So pot them up and re-grow the roots and put the plant in the ground in August."